The present invention relates generally to a cleaning apparatus. More specifically, the present invention relates to a vacuumized squeegee assembly structured for attachment to a floor cleaning system and having improved pickup capabilities.
The use of vacuumized squeegee assemblies for wiping a surface and collecting dirty solution is conventional in many applications including, but not limited to, floor surface cleaning machines such as floor scrubbers. Typically, the front and rear blades of the squeegee assembly are always in contact with the floor surface so that any liquid on the floor surface is exposed to, picked up, and carried by airflow in the squeegee assembly. The rear blade in particular is provided with sufficient downward force to bend the blade outward so that only one edge of the blade engages the floor surface. Exemplary squeegee assemblies incorporating front and rear blades are disclosed in U.S. Pat. Nos. 7,254,867 and 6,557,207.
The surface qualities of the floor are an important factor in the ability of the squeegee assembly to function as desired. As appreciated by those skilled in the art, squeegee assemblies function ideally with a level, smooth floor surface. However, floor surfaces are of a variety of types which are not always level and/or completely smooth such as by design as in the case of grouted tile or textured floors, by necessity or damage such as in the case of seams and/or cracks, or by wear such as rough or pitted surfaces. In those instances, moisture may be located in depressions which may be easily passed over by the blades and/or not exposed to airflow sufficient to be picked up thereby.
FIG. 1 is a diagram illustrating one embodiment of a conventional squeegee assembly. In particular, FIG. 1 illustrates a cross-section of conventional squeegee assembly 10, which generally includes support 12, suction tube 14 structured for connection to a vacuum source, front flexible blade 16, and rear flexible blade 18. Front and rear flexible blades 16 and 18 are spaced apart and attached to an inside surface of support 12 at respective front and rear portions thereof. As illustrated in FIG. 1, front and rear flexible blades 16 and 18 of squeegee assembly 10 are in contact with a floor surface F comprising a plurality of tiles T separated by grout lines G.
During operation of conventional squeegee assembly 10, when front and rear flexible blades 16 and 18 pass over grout line G, air may be taken through the grout line. Such air passing between the rear wiping blade and the grout line channel may assist in removing water from the grout lines or cracks by entraining liquid in the grout line in the rapidly moving air.
However, in some conventional squeegee assemblies, dirty liquid may pool against a portion of the rear flexible blade adjacent the suction tube due to the flow dynamics within the suction chamber formed between the front and rear flexible blades. This phenomenon is illustrated in FIG. 2A, which is a bottom view of squeegee assembly 10 showing a pool of liquid P built-up against rear flexible blade 18 adjacent suction tube 14. In particular, the majority of the liquid is suctioned through suction tube 14 as indicated by the broken lines between front and rear flexible blades 16 and 18 that are directed toward the suction tube. However, a portion of the liquid is not suctioned through suction tube 14, and instead builds-up and forms the pool of liquid P near the center of rear flexible blade 18. Thereafter, when rear flexible blade 18 passes over a grout line, crack, or other irregularity in the floor, a gap is formed between rear flexible blade 18 and the floor surface allowing the pooled dirty liquid P to pass through the gap and splash in a rearward direction leaving behind a puddle on the floor. Such puddles are not only aesthetically displeasing, but they also create safety hazards for individuals who must walk across the floor after the floor has been cleaned.
More particularly, liquid is directed by the curvature of the blades and by the air moving in the direction of the suction tube toward the rearmost portion of the squeegee assembly where it is carried up into a recovery tank. Both air and entrained liquid move along the rear blade and into the suction tube opening during operation of the squeegee assembly. However, as illustrated in FIG. 2B, there is a region of very low air flow near suction tube 14 where the air stream L from the left side of suction tube 14 comes together with the air stream R from the right side of suction tube 14. A significant amount of liquid may be collected in this region, thus creating the pool of liquid P. Consequently, and as depicted in the diagram of rear blade 18 in FIG. 2C, when the rearmost portion of rear blade 18 approaches grout line G (or other surface irregularity), this pool of liquid P will spread into the grout line. After the squeegee assembly passes over grout line G, this liquid may be expelled from grout line G due in part to the action of rear blade 18 slapping the water out as it passes over the grout line.
Several attempts have been made to address the above shortcomings. One attempt has been to increase the strength of the vacuum pump coupled to the suction tube. However, this solution has proved costly and is not ideal due to the increased power demands. Moreover, increasing the strength of the vacuum pump does not eliminate the area of low air flow near the vacuum port. A second attempt has been to increase the suctioning force of dirty liquid by reducing the space between the front and rear flexible blades. However, this solution has not been successful because reducing the space between the front and rear flexible blades limits the width of the suction port, which in turn necessitates an extreme transition from a narrow slotted vacuum port to a round vacuum hose. Such an severe transition adds height to the squeegee assembly and may become easily clogged with debris. As a result, it is almost impossible to suction all of the dirty liquid from grout lines and cracks effectively with a conventional vacuumized squeegee.
Thus, there is a need for a squeegee assembly having improved pickup capabilities. There is a further need for a squeegee assembly that is designed to minimize the pooling of liquid against the rear blade of the assembly.